[MIPS] debuggerd and libcorkscrew support
Change-Id: I5a241dc2e470148be0ad2c138e31f1aba5ab8812
diff --git a/libcorkscrew/arch-mips/backtrace-mips.c b/libcorkscrew/arch-mips/backtrace-mips.c
new file mode 100644
index 0000000..07d4a24
--- /dev/null
+++ b/libcorkscrew/arch-mips/backtrace-mips.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Backtracing functions for mips
+ */
+
+#define LOG_TAG "Corkscrew"
+//#define LOG_NDEBUG 0
+
+#include "../backtrace-arch.h"
+#include "../backtrace-helper.h"
+#include <corkscrew/ptrace.h>
+
+#include <stdlib.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <errno.h>
+#include <sys/ptrace.h>
+#include <sys/exec_elf.h>
+#include <cutils/log.h>
+
+/* For PTRACE_GETREGS */
+typedef struct {
+ /* FIXME: check this definition */
+ uint64_t regs[32];
+ uint64_t lo;
+ uint64_t hi;
+ uint64_t epc;
+ uint64_t badvaddr;
+ uint64_t status;
+ uint64_t cause;
+} user_regs_struct;
+
+/* Machine context at the time a signal was raised. */
+typedef struct ucontext {
+ /* FIXME: use correct definition */
+ uint32_t sp;
+ uint32_t ra;
+ uint32_t pc;
+} ucontext_t;
+
+/* Unwind state. */
+typedef struct {
+ uint32_t sp;
+ uint32_t ra;
+ uint32_t pc;
+} unwind_state_t;
+
+uintptr_t rewind_pc_arch(const memory_t* memory, uintptr_t pc) {
+ if (pc == 0)
+ return pc;
+ if ((pc & 1) == 0)
+ return pc-8; /* jal/bal/jalr + branch delay slot */
+ return pc;
+}
+
+static ssize_t unwind_backtrace_common(const memory_t* memory,
+ const map_info_t* map_info_list,
+ unwind_state_t* state, backtrace_frame_t* backtrace,
+ size_t ignore_depth, size_t max_depth) {
+ size_t ignored_frames = 0;
+ size_t returned_frames = 0;
+
+ for (size_t index = 0; returned_frames < max_depth; index++) {
+ uintptr_t pc = index ? rewind_pc_arch(memory, state->pc) : state->pc;
+ backtrace_frame_t* frame;
+ uintptr_t addr;
+ int maxcheck = 1024;
+ int stack_size = 0, ra_offset = 0;
+ bool found_start = false;
+
+ frame = add_backtrace_entry(pc, backtrace, ignore_depth,
+ max_depth, &ignored_frames, &returned_frames);
+
+ if (frame)
+ frame->stack_top = state->sp;
+
+ ALOGV("#%d: frame=%p pc=%08x sp=%08x\n", index, frame, frame->absolute_pc, frame->stack_top);
+
+ for (addr = state->pc; maxcheck-- > 0 && !found_start; addr -= 4) {
+ uint32_t op;
+ if (!try_get_word(memory, addr, &op))
+ break;
+
+ // ALOGV("@0x%08x: 0x%08x\n", addr, op);
+ switch (op & 0xffff0000) {
+ case 0x27bd0000: // addiu sp, imm
+ {
+ // looking for stack being decremented
+ int32_t immediate = ((((int)op) << 16) >> 16);
+ if (immediate < 0) {
+ stack_size = -immediate;
+ found_start = true;
+ ALOGV("@0x%08x: found stack adjustment=%d\n", addr, stack_size);
+ }
+ }
+ break;
+ case 0xafbf0000: // sw ra, imm(sp)
+ ra_offset = ((((int)op) << 16) >> 16);
+ ALOGV("@0x%08x: found ra offset=%d\n", addr, ra_offset);
+ break;
+ case 0x3c1c0000: // lui gp
+ ALOGV("@0x%08x: found function boundary\n", addr);
+ found_start = true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (ra_offset) {
+ uint32_t next_ra;
+ if (!try_get_word(memory, state->sp + ra_offset, &next_ra))
+ break;
+ state->ra = next_ra;
+ ALOGV("New ra: 0x%08x\n", state->ra);
+ }
+
+ if (stack_size) {
+ if (frame)
+ frame->stack_size = stack_size;
+ state->sp += stack_size;
+ ALOGV("New sp: 0x%08x\n", state->sp);
+ }
+
+ if (state->pc == state->ra && stack_size == 0)
+ break;
+
+ if (state->ra == 0)
+ break;
+
+ state->pc = state->ra;
+ }
+
+ ALOGV("returning %d frames\n", returned_frames);
+
+ return returned_frames;
+}
+
+ssize_t unwind_backtrace_signal_arch(siginfo_t* siginfo, void* sigcontext,
+ const map_info_t* map_info_list,
+ backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) {
+ const ucontext_t* uc = (const ucontext_t*)sigcontext;
+
+ unwind_state_t state;
+ state.sp = uc->sp;
+ state.pc = uc->pc;
+ state.ra = uc->ra;
+
+ ALOGV("unwind_backtrace_signal_arch: ignore_depth=%d max_depth=%d pc=0x%08x sp=0x%08x ra=0x%08x\n",
+ ignore_depth, max_depth, state.pc, state.sp, state.ra);
+
+ memory_t memory;
+ init_memory(&memory, map_info_list);
+ return unwind_backtrace_common(&memory, map_info_list,
+ &state, backtrace, ignore_depth, max_depth);
+}
+
+ssize_t unwind_backtrace_ptrace_arch(pid_t tid, const ptrace_context_t* context,
+ backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth) {
+
+ user_regs_struct regs;
+ if (ptrace(PTRACE_GETREGS, tid, 0, ®s)) {
+ return -1;
+ }
+
+ unwind_state_t state;
+ state.sp = regs.regs[29];
+ state.ra = regs.regs[31];
+ state.pc = regs.epc;
+
+ ALOGV("unwind_backtrace_ptrace_arch: ignore_depth=%d max_depth=%d pc=0x%08x sp=0x%08x ra=0x%08x\n",
+ ignore_depth, max_depth, state.pc, state.sp, state.ra);
+
+ memory_t memory;
+ init_memory_ptrace(&memory, tid);
+ return unwind_backtrace_common(&memory, context->map_info_list,
+ &state, backtrace, ignore_depth, max_depth);
+}